The speed-density fuel-injection system uses the sensor as the primary sensor to determine base pulse width.
A. TP (throttle position)
B. MAF (mass air flow)
C. MAP (manifold absolute pressure)
D. BARO (barometric)
The correct answer and explanation is :
The correct answer is A. TP (Throttle Position).
Explanation:
In a speed-density fuel injection system, the primary sensors play a crucial role in determining the correct amount of fuel to inject into the engine. These systems are designed to calculate the air-fuel ratio by measuring various factors such as engine load, air intake, and engine speed. The throttle position (TP) sensor is one of the key sensors used in this system to help calculate the fuel injection pulse width, which is the duration for which the fuel injectors remain open.
Here’s a detailed breakdown of the sensors involved and why the throttle position (TP) sensor is the correct answer:
- Throttle Position (TP) Sensor:
- The TP sensor measures the position of the throttle plate in the throttle body, which is directly related to the driver’s input on the accelerator. The throttle position tells the engine control unit (ECU) how much air is being allowed into the engine, which is an essential factor in calculating the required fuel. In speed-density systems, the ECU uses this information, in conjunction with engine speed (RPM) and other data, to adjust the base pulse width for fuel injection.
- As the throttle position changes, the airflow into the engine changes, influencing the fuel demand. The ECU uses this data to optimize fuel delivery, ensuring proper combustion under different driving conditions.
- Mass Air Flow (MAF) Sensor:
- A MAF sensor measures the amount of air entering the engine and is often used in mass-airflow-based fuel systems. However, speed-density systems do not rely on the MAF sensor but instead calculate air intake indirectly through pressure and temperature measurements.
- Manifold Absolute Pressure (MAP) Sensor:
- The MAP sensor measures the pressure inside the intake manifold. While important in speed-density systems for estimating engine load and airflow, it does not directly determine the base pulse width of fuel injection. It provides additional input to the ECU.
- Barometric (BARO) Sensor:
- The BARO sensor measures atmospheric pressure, typically used to adjust for altitude. While it can affect fuel calculations, it is not the primary sensor for determining the base pulse width.
Thus, the TP sensor is the primary sensor used in a speed-density system for determining the base pulse width, adjusting fuel delivery based on throttle input and engine load.
